1. Field of the Invention
The invention relates to a multi-view video coding method, and more particularly to a multi-view video coding method using a hierarchical B-picture (HBP) prediction structure.
2. Description of the Related Art
FIG. 1 illustrates a conventional multi-view video coding method using a hierarchical B-picture (HBP) prediction structure. The HBP prediction structure includes a plurality of image sequences, each of which includes a plurality of pictures that are captured from an individual viewpoint (S0, S1, S2, S3, S4) at consecutive time-points (T1, T2, T3, T4, T5, T6, T7, T8). In each image sequence, two pictures corresponding respectively to the time-points (T0, T8) denote anchor pictures, and the other pictures denote non-anchor pictures. For each of the image sequences corresponding to the viewpoints (S0, S2, S4), video data in each non-anchor picture is encoded by using two pictures in the same image sequence corresponding to two other time-points as references. For example, the video data of the B1 picture corresponding to the viewpoint (S0) and the time-point (T4) is encoded by using the I picture corresponding to the viewpoint (S0) and the time-point (T0), and the I picture corresponding to the viewpoint (S0) and the time-point (T8). For each of the image sequences corresponding to the viewpoints (S1, S3), video data in each non-anchor picture is encoded by using two pictures in the same image sequence corresponding to the two other time-points, and two pictures from two adjacent image sequences corresponding to the same time-point. For example, video data in the B3 picture corresponding to the viewpoint (S1) and the time-point (T2) is encoded by using the B1 picture corresponding to the viewpoint (S1) and the time-point (T0), the B2 picture corresponding to the viewpoint (S1) and the time-point (T4), the B2 picture corresponding to the viewpoint (S0) and the time-point (T2), and the B2 picture corresponding to the viewpoint (S2) and the time-point (T2). From this example, the pictures in the image sequence corresponding to the viewpoint (S2) have to be encoded before the pictures in the image sequence corresponding to the viewpoint (S1) are encoded. Similarly, the pictures in the image sequence corresponding to the viewpoint (S4) have to be encoded before the pictures in the image sequence corresponding to the viewpoint (S3) are encoded.
It is noted that, during encoding of each non-anchor pictures in each of the image sequences corresponding to the viewpoints (S1, S3), there are four pictures typically used as references, thereby resulting in a huge amount of computation and longer processing time. In addition, a relatively large number of encoding/decoding picture buffers are required. As such, improvements may be made to the above techniques.